TGFB1 and cancer: To conclude, the effect of Vit C on γδ T cell plasticity depends on the overall environmental signals.166,167 As discussed above, Vit C actually conveys a regulatory phenotype and induces FOXP3 hypomethylation in the additional presence of TGF-β.112 However, in the absence of TGF-β during the expansion phase, Vit C substantially enhances effector functions desired in the context of cancer immunotherapy.